It would be possible that one professor might have not remembered Obama, but not all of them.
My guess is he got a free ride into Columbia via the wealthy Saudi who donated millions around that same time. And, it was probably best he did not go to any classes especially if he was not a good student - he would have stuck out and had been remembered as the student who couldn't cut it.
It is strange that your ILL request was not filled, because librarians are more than happy to search for everything.
Most librarians are liberal. They could be in on it.